Membrane proteins and glycoproteins from the flagellum of Euglena are being characterized separately from those of the remainder of the cell surface. A number of specific surface glycoproteins appear to be confined only to the flagellum even though the flagellar membrane is continuous with the cell membrane. Efforts are being directed to obtain specific antibody to the unique flagellar components and to determine by using immunospecific label, the route and mechanism of insertion into the flagellar membrane. A second phase of this project is designed to isolate three different microtubule protein pools in Euglena. Each pool (flagellum, nucleus, cytoplasm) can be separately isolated, and attempts are being made to obtain samples from each compartment for analysis on 2-D acrylamide gels and for peptide fragment analysis. Eventually it is anticipated it will be possible to assess the inter-changeability of separate tubulin pools, and to assess priorities for their utilization under different physiological conditions. BIBLIOGRAPHIC REFERENCES: Bouck, G.B. and Green, P.M. 1976. Paracrystals and mastigonemes are directly attached to the Euglena axonemal microtubules. J. Cell. Biol. 70:156A. Markey, D.M. and Bouck, G.B. 1977. Mastigoneme attachment in Ochromonas. J. Ultrastruct. Res. 59:173-177.